1. In the first Hierarchy:
evoked by the utterance of prayer, work of the Angels;
heard in study and reading, work of the Archangels;
announced through example and preaching, work of the Principalities.
2. In the second Hierarchy:
joined with refuge and place of indulgence, work of the Powers;
apprehended through zeal and emulation,
work of the Virtues;
conjoined with self-deprecation and mortification,
work of the Dominions.
3. In the third Hierarchy:
worshipped through sacrifice and praise,
work of the Thrones;
admired through ecstasy (going out of oneself)
embraced in kiss and dilection (amplectanda per osculum et dilectionem),
work of the Seraphim.
Note diligengly what I say here,
because this is the fountain of life.
St Bonaventura, De triplici via, iii, 14